The invention relates to a visually indicating bovine teat dip composition that can be mixed using two parts, a simple chlorite solution and an acid or acidulant formulation, to form a stable, effective composition that can be used in routine dairy procedures.
Bovine mastitis is the most common and most costly disease affecting dairy herds. Some estimates suggested at least half of the dairy animal population have some degree or form of mastitis. This condition results in lowered milk yield and reduced quality. Economic loss to mastitis in the U.S. is estimated at about $1.8 billion or approximately 10% of total milk sales with about two-thirds of this loss due to reduced milk production from infected cows. Mastitis is an inflammation of the mammary gland. Similarly, inflammation is one response of a tissue or organ to insult or injury. An injury caused by physical, chemical or thermal trauma can produce an inflammatory response. In the dairy cow, mastitis typically results from microorganisms, usually bacteria, that invade the udder, multiply in the delicate milk producing tissues, and synthesize toxins, a by-product of bacterial metabolism. The characteristic features of inflammation are swelling, heat, redness, pain and disturbed function.
While the animal immune system can fight intramammary infections, many chronic infections remain sub-clinical (asymptomatic) and undetected unless diagnosed by laboratory testing. Sub-clinical mastitis can result in a reservoir of micro-organisms that leads to the infection of other animals within the herd. More than 80 species of microorganisms have been identified as causal agents, although approximately 95% of mastitis is caused by four pathogens; Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysagalactiae, and Streptococcus uberis. Mastitis causing pathogens fall into two categories namely contagious and environmental. Contagious bacteria, such as Streptococcus agalactiae and Staphylococcus aureus, primarily colonize host tissue sites such as mammary glands, teat canals, teat skin lesions etc. and are spread from one infected cow to another during the milking process. Environmental bacteria, often streptococci, enterococci and coliform organisms, are commonly present within the cow""s surroundings from sources such as cow feces, soil, plant material, bedding or water, and infect by casual opportunistic contact with an animal during the inter-milking period. This distinction, although not exclusive, is of practical importance because different dairy herd maintenance measures are needed for the different groups of microorganisms. In all bovine mastitis cases, whatever the causal microorganism, the route of transmission of the invading pathogen into the inner gland of the udder is through the teat orifice and teat canal.
Management of dairy herds focuses attention on treatment of both established mastitis and on prevention of new intramammary infections. Therapy and hygiene are the two fundamental components of an effective mastitis control protocol. Each is applied in concert, and each operates independently. The primary effect of therapy is to increase the rate of eliminating established infections; whereas, hygiene reduces the frequency of infection by interrupting transmission vectors. We cannot present all ancillary factors that may be employed for the elimination and prevention of mastitis, however, the most effective therapy and hygiene practices are, respectively, antibiotic infusion treatment of the udder""s four quarters at the end of lactation; and, post-milking teat antisepsis or xe2x80x9cteat dippingxe2x80x9d during lactation.
Researchers agree, and an abundance of published evidence supports the concept, that dipping teats into an effective antimicrobial solution immediately after each milking is the single most effective procedure for decreasing new intramammary infections in lactating cows. Between 1955 to 1970, Dodd and co-workers (F. K. Neave, F. H. Dodd, and R. G. Kingwell, 1966, xe2x80x9cA Method of Controlling Udder Diseasexe2x80x9d, Vet. Rec. 78:521; F. K. Neave, F. H. Dodd, R. G. Kingwell and D. R. Westgarth, 1969, xe2x80x9cControl of Mastitis in the Dairy Herd by Hygiene and Managementxe2x80x9d, J. Dairy Sci. 52:696; F. H. Dodd, D. R. Westgarth, F. K. Neave and R. G. Kingwill, 1969, xe2x80x9cMastitisxe2x80x94The Strategy of Controlxe2x80x9d, J. Dairy Sci. 52:689; and F. H. Dodd, and F. K. Neave, 1970, xe2x80x9cMastitis Controlxe2x80x9d, Proceedings, Nat""l. Inst. Res. Dairying, pp. 21-60) conducted extensive epidemiologic investigations in commercial dairy herds. From this work, they developed the conceptual basis for modern mastitis control methods of which teat dipping is an integral component. The efficacy and value of teat dipping has since been confirmed in dozens of field trials, and it is now accepted that an effective teat dip can reduce the incidence of new intramammary infections at least 50% and often up to 90%.
To reduce mastitis, commercial teat dips have been developed containing a variety of antimicrobial agents including iodophors, quaternary ammonium compounds, chlorhexidine salts, chlorine release compounds (e.g. alkali hypochlorites), oxidizing compounds (e.g. hydrogen peroxide, peracids), protonated carboxylic acids (e.g. heptanoic, octanoic, nonanoic, decanoic, undecanoic acids), acid anionics (e.g. alkylaryl sulfonic acids), and chlorine dioxide (from chlorite). These agents, which have varying degrees of effectiveness, limit the transmission of mastitis by reducing pathogen populations on the teat. Teat dips, can also be divided into two broad classifications. The Class I type are antimicrobial and are applied to kill microorganisms already present in the teat canal or on the surface of the teat skin. By design, their microbiological effect is immediate and their targets primarily the contagious organisms that are vectored between animals during the pre-milking, milking and post milking process. The Class II type teat dip, often referred to as a xe2x80x9cteat sealer,xe2x80x9d is a film-forming or coating composition which may or may not be antimicrobial; and, functions by developing a residual protective barrier on the teat thus providing prophylaxis by sealing the teat off from its environment. The film which forms on the surface of the teat serves as a physical barrier through which mastitis causing pathogens cannot penetrate during the intermilking period.
General disclosures of teat dip technology are shown in: xe2x80x9cCurrent Concepts of Bovine Mastitis.xe2x80x9d 1996, Fourth Ed. National Mastitis Council, Madison Wis.; P. A. Murdough and J. W. Pankey, 1993. xe2x80x9cEvaluation of 57 Teat Sanitizers Using Excised Cow Teatsxe2x80x9d, J. Dairy Sci. 76:2033-2038; J. W. Pankey et al., 1984, xe2x80x9cUptake on Post-milking Teat Antisepticsxe2x80x9d, J. Dairy Sci. 67:1336-1353; R. J. Farnsworth, 1980, xe2x80x9cRole of Teat Dips in Mastitis Controlxe2x80x9d, J. Am. Vet. Med. Assoc. 76:1116-1118; W. N. Philpot, 1979, xe2x80x9cControl of Mastitis by Hygiene and Therapyxe2x80x9d, J. Dairy Sci. 62:168-176; W. N. Philpot and J. W. Pankey, 1978, xe2x80x9cHygiene in the Prevention of Udder Infections V. Efficacy of Teat Dips Under Experimental Exposure to Mastitis Pathogensxe2x80x9d, J. Dairy Sci. 61:956-963; R. P. Natzke, 1977, xe2x80x9cRole of Teat Dips and Hygiene is Mastitis Controlxe2x80x9d, J. Amer. Vet. Med. Assoc. 170:1196-1198; W. N. Philpot and J. W. Pankey, 1975, xe2x80x9cHygiene in the Prevention of Udder Infections. III. Effectiveness of 59 Teat Dips for Reducing Bacterial Populations on Teat Skinxe2x80x9d, J. Dairy Sci. 58:209-216; R. J. Eberhart and J. M. Buckalew, 1972, xe2x80x9cEvaluation of a Hygiene and Dry Period Therapy Program for Mastitis Controlxe2x80x9d, J. Dairy Sci. 55:1683-1691; W. D. Schultze and J. W. Smith, 1972, xe2x80x9cEffectiveness of Postmilking Teat Dipsxe2x80x9d, J. Dairy Sci. 55:426-431; D. P. Wesen and L. H. Schultz, 1970, xe2x80x9cEffectiveness of a Post-Milking Teat Dip in Preventing New Udder Infectionsxe2x80x9d, J. Dairy Sci. 53:1391-1403; and British Pat. No. 1,144,637 (Kelco Chemicals Ltd.), published Mar. 5, 1969. U.S. Pat. No. 4,199,602 (Lentsch) issued Apr. 22, 1980, U.S. Pat. No. 4,258,056 (Lentsch) issued Mar. 24, 1981; and U.S. Pat. No. 4,376,787 (Lentsch) issued Mar. 15, 1983 disclose nitroalkanol, amino carboxylate/sulfonate, and sulfonate based compositions. U.S. Pat. No. 4,446,153 (Yang) issued May 1, 1984 discloses a benzyl alcohol/phenyl ethanol based composition.
Typical disclosures of intermilking or protective (barrier-type) film-forming teat dips or teat xe2x80x9csealersxe2x80x9d can be found in Akers et. al., U.S. Pat. No. 3,066,071, issued Nov. 27, 1962; Kraus, U.S. Pat. No. 3,222,252, issued Dec. 7, 1965 (but, see Philpot et. al., J. Dairy Science 58:205-216); Coughman and Brown, U.S. Pat. No. 3,993,777, issued Nov. 23, 1976; Pugliese, U.S. Pat. No. 4,049,830, issued Sep. 20, 1977; and Andrews et al., U.S. Pat. No. 4,113,854, issued Sep. 12, 1978. A teat sealer similar or identical to the Andrews et. al. film-forming composition is in commercial use and has been discussed in the dairy science literature. See, for example, R. J. Farnsworth et. al., 1980, xe2x80x9cUse of a Teat Sealer for Prevention of Intramammary Infections in Lactating Cowsxe2x80x9d, J. Am. Vet. Med. Assoc. 177:441-444; and R. J. Farnsworth et. al., 1981, xe2x80x9cThe Effect of a Teat Sealer on Coliform Mastitisxe2x80x9d, The Bovine Practitioner, No. 16, pp. 28-29. Still further examples of barrier-type film-formers for bovine teats can be found in Silver et al., U.S. Pat. No. 4,199,564, issued Apr. 22, 1980; Dybas et al., U.S. Pat. No. 4,311,709, issued Jan. 19, 1982; Marhavka , U.S. Pat. No. 5,017,369, issued May 21, 1991; and Schmidt et al., U.S. Pat. No. 5,503,838, issued Apr. 2, 1996.
Persons skilled in the art of bovine mastitis treatment know that antimicrobial teat dip compositions (Class I type) which do not form protective films with barrier properties have a shortened residual time on the teat and their efficacy is quickly lost due to adsorption, ion-pairing, oxidation or simply sloughing off. Furthermore, such teat dips often fail to retard the entrance of bacteria into the teat canal during the intermilking period and provide no protection to the teat from irritation caused by wind, sun or contact abrasion. As disclosed in the art, attempts have been made to provide antimicrobial teat dips containing film-forming materials designed to form protective barriers on the skins of the teats; and, to afford continuous protection against mastitis causing pathogens, both contagious and environmental, and, from irritation caused by exposure to adverse environmental elements.
Early researchers discovered that incorporating a film-forming, protective barrier system into an antimicrobial teat dip was fraught with technical problems, either physicochemical problems with the composition or application/performance problems in practice. The best prophylactic barriers, and most environmentally durable, are water insoluble synthetic organics made up of homopolymers or heteropolymers of two or more different monomers. These are applied either from volatile solvent based compositions or by film-forming polymer latexes which are suspensions of a water insoluble polymer in water. U.S. Pat. No. 3,066,071 typifies the former type; and U.S. Pat. No. 4,113,854 discloses compositions typical of the latter kind. Typically, barrier films formed upon teats when applied from a volatile solvent based mastitis dip composition are not user, animal or environmentally friendly. In practice, these materials subject the skin of the teat to the drying, irritating effects of organic solvents. Compositions containing a film-forming polymer latex overcome volatile solvent concerns as polymer latexes are most often suspensions of a water insoluble polymer(s) in water; however, commercial latexes necessarily include stabilizers, preservatives, suspending agents etc. which add complexity; and, as such are frequently incompatible with the most preferred and most efficacious antimicrobial agents. All water insoluble polymeric films, which generally form a flexible almost rubbery film on the teat skin, must be removed by peeling. In practice, such mastitis control compositions have not received widespread acceptance because of the inconvenient, time-consuming, often troublesome removal process prior to milking.
U.S. Pat. No. 3,222,252 describes a bovine teat dip consisting of vegetable oils of the drying or semi-drying types and certain fatty acid esters. In concept, this disclosure bridges the gap between synthetic polymer coatings and natural polymer coatings. In practice, oil based dips have proved to be ineffective in preventing mastitis, and they are difficult to remove from the teats. In fact, their use has tended to increase the incidence of mastitis (see Philpot et. al, J. Dairy Science 58:205-216).
U.S. Pat. No. 3,993,777, referenced above, discloses an aqueous thickened quat based formulation of high viscosity containing emollients such as lanolin and glycerin. The material forms a protective film and bacteriostatic barrier about the teat which is easily removed by washing; thus, transitioning from water insoluble protective films which in practice are peeled from the teat to water washable films. However, the shortfall of this teaching is the use of hydroxyethylcellulose employed as a thickener (its most typical function) in the preferred formulation which, by chance, has the characteristic of forming pliable non-brittle films upon drying. In herd practice, such cellulosic thickeners seldom perform the dual-function role of providing a tenacious barrier, being too readily removed because of its water-sensitivity, wherein the performance of the antimicrobial barrier is lost. U.S. Pat. No. 4,311,709 also discloses a film-forming methycellulose having similar disadvantage as a teat dip barrier. U.S. Pat. No. 4,049,830 discloses a bovine teat dip composition which delivers an oil-in-water emulsion to the teat and, upon drying, forms an antimicrobial lipid solids barrier which remains soft and tacky for prolonged periods and is water washable. Herd experience has shown that soft barriers are too easily abraded or otherwise sloughed off during the intermilking period with subsequent reduction or loss of biocidal function. U.S. Pat. No. 5,017,369 discloses antimicrobial mastitis treatment compositions which utilize a water resistant film-forming agent, polyvinyl alcohol. This art teaches away from incorporation and use of thickener admixtures, suggesting that adequate viscosity can be obtained simply by adjusting the amount of polyvinyl alcohol in the composition. Such compositions are, in application, at commercial disadvantage because polyvinyl alcohol by itself does not provide effective teat cling nor does it decrease the mobility of the dipping liquid which is manifested by excessive drain-off and loss of product; and, therefore significant reduction of barrier function and microbial performance. U.S. Pat. No. 5,503,838 overcomes this disadvantage in disclosing antimicrobial teat dip compositions containing polyvinyl alcohol in cooperation with thickening agents such as a xanthan gum. Unfortunately, neither U.S. Pat. No. 5,017,369 which typically embodies chlorhexidene gluconate or quaternary ammonium compounds as the antimicrobial; nor, U.S. Pat. No. 5,503,838 which uses iodine as the preferred biocidal agent, address the issue of teat dermal irritation caused by residual barrier films containing resident, chemically aggressive, often toxic, antimicrobial agents which remain on skin contact for extended periods of time.
Alliger, U.S. Pat. No. Re. 31,779, reissued Dec. 25, 1984; Alliger, U.S. Pat. No. 4,330,531 (Alliger) issued May 18, 1982; Kross et al., U.S. Pat. No. 4,891,216, issued Jan. 2, 1990; Davidson et al., U.S. Pat. No. 4,986,990, issued Jan. 22, 1991; Davidson et al., U.S. Pat. No. 5,185,161, issued Feb. 9, 1993; and Kross, U.S. Pat. No. 5,597,561 disclose technology embodied in a commercial composition sold as an antimicrobial barrier teat dip under the name UDDER-GOLD PLUS (Alcide Corp., Redmond, Wash.). The patents disclose two aqueous solutions, described as gels, adapted to be mixed in a 50/50 proportion wherein (according to patent and product literature) chlorous acid/chlorine dioxide are generated by chemical reaction of I-hydroxy-benzene-acetic acid (mandelic acid) and sodium chlorite present in first and second gels respectively. The second gel can contain a thickener. Later patents disclose a homopolymer of 2-acrylamido-2-methylpropane sulfonic acid (polysulfonic acid) which forms a protective film over the teat. Although this composition has proven effective, it is not without problem. The herdsman is advised to mix and use the admixture for only one herd milking, discarding any extra. This attribute is likely a consequence of chlorine dioxide loss (hence, loss of antimicrobial efficacy) either from chemical incompatibility and/or off-gassing. The polysulfonic acid xe2x80x9cgelling agentxe2x80x9d does not immobilize the treatment on the teat and significant drippage/waste occurs. U.S. Pat. No. 5,597,561 teaches that polysulfonic acid has proven problematic because of its strong affinity to the dermal tissue and tendency to form a solid matrix which is difficult to remove by washing.
Richter, U.S. Ser. Nos. 08/038,064 and 08/038,553, and U.S. Pat. No. 6,379,685, disclose basic teat dip technology. These systems are two part chlorite and acid materials that when blended form a protective layer or coating. The utility or effectiveness of these systems can be enhanced by the presence of a marker dye showing the location of the treatment on or adhering to the animal. Simply including a dye in the chlorite part, however, or in the combined materials, is often not fully effective. The oxidizing nature of chlorite (ClO2xe2x88x921) or chlorine dioxide (ClO2) can rapidly alter or bleach the typical added color.
A substantial need remains after all these attempts, for long lasting protective, film or shield forming barrier-type teat dip compositions having a visual indicator or unique color that can indicate the presence of an immediate and long lasting antimicrobial effect against a wide spectrum of mastitis causing organisms. The visual indicator can also indicate the presence of an active effective amount of ClO2.
We have discovered a mastitis control treatment having important functional properties that are uniquely combined into one composition. The compositions of the invention can contain a visual indicator material. Such an indicator material can be useful in blending the material to show the presence of an active chlorine dioxide component, can be used to demonstrate the location of the material on the animal skin, can be used as an indication of active chlorine dioxide in the material formed on the animal skin, or can be an indicator of the presence of active material in the blended composition showing an extended shelf life after blending. Such a visual indicator material can be prepared using one of a number of options. First, urea has been found to stabilize the dye blended into the overall composition or included in the acid or organic phase of the composition. The urea material used to stabilize the dye has also been shown to modulate the production and/or release of chlorine dioxide by the blended material. The teat dip material provides a reduced rate of release of the chlorine dioxide into the active blend, thus somewhat reducing the effective concentration of the chlorine dioxide in the material but greatly extending the lifetime of the material having an effective concentration of chlorine dioxide. In this way, wasteful production of chlorine dioxide does not occur while the delayed production of the chlorine dioxide maintains a lower, but more efficient concentration of chlorine dioxide in the material formed on the animal skin. A second embodiment of the invention involves a dye or combination of dyes that show that the sodium chlorite part is blended with the acid part and has been blended to a uniform active composition. A dye or blend of dyes can be used to produce a color change in the resulting blended material. In one embodiment, a pH sensitive dye can be included in the acid part that is converted to a different color by the change in pH as the sodium chlorite part is blended with the acid part. The pH of the original acid part is typically approximately 2.7, while the pH of the blended part is typically greater than 3.0. Such a color change can be helpful. Such a color change can be produced using a single stable dye or a stable dye blended with a relatively unstable dye effectively showing a visual dramatic color change upon blending. A further embodiment of the invention involves dispersing a dye or pigment in an oil phase. The oil phase containing the dye can maintain the dye in a separate phase apart from the oxidative material in the aqueous blended phase. One aspect of this embodiment involves the use of a xe2x80x9cdrying oilxe2x80x9d that, in the presence of oxidative systems, can crosslink to substantially increase the viscosity of the oil phase, thus substantially reducing the tendency of the dye to be leached from the oil phase into the aqueous phase. Maintaining the dye in the oil phase protects the dye from aqueous oxidation by the oxidative systems. A last embodiment of the visual indicator of the invention is a chemiluminescent material that can be used. The chemiluminescent material involves materials that can be blended to produce the characteristic soft glow produced by chemiluminescence. The compositions would be formulated such that the chemiluminescent glow is produced only upon blending and would continue to glow only as long as an effective concentration of oxidant remained in the composition. Such a glow would provide an indication to the blender that the composition was uniformly blended and that the composition maintained a high level of activity for an extended period of time. The glow would tend to subside as the active material dropped in concentration upon storage.
The first embodiment of the invention provides a stable visual indicator or color using a dye or a mixture of dyes. The dye color is maintained by one of the disclosed stability systems. The dye stability can be the result of the use of either a stabilizing amount of urea, the use of chemiluminescent systems that are activated by an oxidant or the dye can be incorporated into a non-aqueous phase and maintained apart from the oxidative nature of the chlorine species in aqueous solution. The stable indicated materials of the invention also provide a soothing softening emollient character, rapid initial kill, long lasting antimicrobial activity, a stable chemistry and rheology. The blend of lanolin composition and polyhydroxy emollients provide enhanced softening, smoothing, soothing character to treated skin. The compositions of the invention possess favorable rheology that promotes cling and immobilizes the mastitis treatment on the teat. The composition develops a barrier giving prophylactic protection and containing at least one resident agent for continuous biocidal protection. The composition does not cause dermal irritation and, is removable by a simple water-washing technique. The barrier has sufficient adherence to withstand premature loss of integrity due to abrasion of environmental conditions. Compositions of this invention are mastitis control and prevention treatments often described as xe2x80x9cteat dips,xe2x80x9d though of course methods of topical aseptic application other than immersion or xe2x80x9cfloodingxe2x80x9d might be used by the herdsman; for example, spraying, brushing, swabbing or foaming onto the teats. When employed as a teat dip, which is a particularly effective practice of application, the teats of the animal are dipped into a reservoir or receptacle containing a composition of the present invention; whereupon, the source is removed, and, preferably one-half to three-fourths of the distal teat has been coated with treatment. After application (by whatever method), the resident treatment adheres onto the teat until drying occurs and development of a protective film results which provides an antimicrobial barrier and prophylactic shield thus protecting the teat from pathogens and adverse environmental factors.
The mastitis control compositions of the invention comprise components dissolved or suspended in an aqueous carrier or medium. The components of the compositions include a chlorine dioxide generating chemical such as sodium chlorite, an acidulant that can contain a protic acid component and an active antimicrobial acid component, an organic film-forming agent, rheology modifying materials, a hydrotrope, an emollient, a surfactant, a buffer if needed, a colorant and other optional materials.
A pseudoplastic aqueous rheology is effected in the composition of the invention by admixtures of polymeric materials such as a xanthan gum and polyvinyl alcohol compositions. When shear stress is applied to the composition (i.e., dipping), product viscosity is reduced allowing easy and rapid application to the teat; and, upon the release of shear (i.e., removal of source), total viscosity recovery occurs almost instantaneously immobilizing the coating, providing cling and assuring little waste by drippage. Further, said compositions have little or no viscoelastic character which thus allows the treatment to flow and to coat the teat smoothly, forming a continuous efficacious layer over the skin of the teat without formation of mucilage streamers as the applicator is withdrawn. The compositions flow slightly down the teat following application to form a thicker layer or xe2x80x9cplugxe2x80x9d across the orifice of the teat canal; and, thus cause a more effective prophylactic barrier against bacteria entering the teat canal.
An occlusive polymeric barrier/film-forming attribute is contributed by inclusion of intermediate or fully hydrolyzed polyvinyl alcohol. Carefully composed polyvinyl alcohol compositions of this invention provide to the mastitis control treatment, after drying, a balanced barrier layer which remains pliable and maintains integrity on the teat; which can be rendered antimicrobial by envelopment of biocidal agents; which does not cause irritation; and, which provides significantly improved and prolonged protection to the teat during the intermilking period by structured adherence, yet does not sacrifice ease of removal prior to milking.
A unique preferred antimicrobial composition is accomplished that can contain one fugitive biocidal agent, chlorine dioxide, and one or more non-fugitive acid biocidal agents such as a C6-12 carboxylic acid, including heptanoic acid, pelargonic acid (nonanoic acid), etc.; an anionic sulfonate, including dodecylbenzenesulfonic acid, and other acidic antimicrobials and mixtures thereof. Such admixtures provide superior cooperative antimicrobial effect. The combined agents provide an immediate, additive biocidal action to contagious mastitis causing pathogens present on the teat when the composition is first applied. A continuous, longer term antimicrobial action is afforded by the non-volatile agents which become enveloped into the barrier film upon drying. Chlorine dioxide, formed in situ by reacting ingredients within the composition, is present only during the initial application of treatment onto the teat and can off-gas during treatment dry-down. This effect is advantageous because the superior antimicrobial properties of chlorine diodide are utilized to destroy the pathogens of greatest concern to the herdsman, i.e., the contagious mastitis causing organisms already on the teat and in the distal teat canal orifice; but, once applied, chlorine dioxide dissipates and thus removes the potential for severe teat skin irritation which otherwise might result from this very reactive chemical; and, for any incidental residuals in the producers milk. Heptanoic acid or nonanoic (pelargonic) acid, which are preferred antimicrobial agents within compositions of the present invention, and/or dodecylbenzenesulfonic acid, all being of non-volatile character, augment the biocidal performance of chlorine dioxide upon initial application; and, as treatment drying occurs with subsequent barrier formation, become resident within the prophylactic coating wherein the agents provide continuous and efficacious antimicrobial protection from mastitis causing environmental organisms. After the chlorine dioxide component, made in situ by the combination of the aqueous acidulant part with the aqueous chlorite part, becomes volatilized and is thus removed from the composition, the composition maintains extended antimicrobial activity and the composition maintains an effective barrier, including a milk duct plug, to environmental pathogens and soils.
Surprising and unexpected long term chlorine dioxide residence and chemical stability results in practice which is in distinct contrast to commercial embodiments of prior art, specifically and particularly the commercial antimicrobial teat dip sold under the name UDDER-GOLD PLUS (Alcide Corp. Redmond, Wash.), having affixed use instructions which advise the user to blend, in equal proportions, only sufficient admixture of cooperative parts (UDDER-GOLD PLUS BASE and UDDER-GOLD PLUS ACTIVATOR) for one herd milkingxe2x80x94discarding any remainder.
We have discovered that preferred mastitis treatment compositions of this invention, once having formed chlorine dioxide in situ from chemical reactants blended together by the herdsman in preassigned proportion, retain this antimicrobial agent and associated antimicrobial property within the admixed teat treatment for extended periods of time. A typical useful application life span of such product being approximately one month following preparatory blending. We believe this unusual chlorine dioxide stability is an additional consequence of the Theological properties of the preferred compositions whereby the chlorine dioxide gas is entrapped and held homogeneously dispersed throughout the product. Such attribute has many practical advantages for the herdsman including convenience of preblending large mixtures of teat treatment and eliminating need for repeatedly preparing the exact quantity applied at each milking, reducing wasteful and costly disposal of unused, but unstable product which cannot be saved for next milking; and, enhanced safety for the user who would otherwise be exposed to off-gassing chlorine dioxide fumes during the milking process.
The compositions of the invention comprise an admixture comprised of two cooperative parts: The first part, of major or equal proportion, having, in aqueous liquid mixture, an acid component and the plurality of components used in the mastitis control compositions of this invention and including all ingredients of organic structure including rheology modifiers and thickeners; emollients, humectants, conditioners and medicaments; surfactants and hydrotropes; antimicrobial agents and preservatives; buffers, acidulants; chromophores and the like: The second part, of equal or minor proportion, being a chlorous acid or salt thereof, more specifically, an alkali metal chlorite; being of aqueous liquid, particulate-powder, or compressed or cast molten solid form; and, generally in practice, added to the first part of the admixture. Further, the aforementioned second part must, if liquid, be readily miscible or, if solid, be easily soluble within the first part to effect rapid homogeneous blending which is of particular importance when large quantities of this admixture are prepared on site by the herdsman. Experience has taught that favorable admixture blending is best accomplished by liquids of the second part having no ordered structure, i.e. no thickened or gelled character; and, by solids of the second part having large surface area. In practice, this means liquids having fluid characteristics similar to water, and solids having particulate form.
The primary function of the second part is to carry the chlorine dioxide release agent into the admixture of this mastitis control treatment; however, lesser adjuvants may be included within, e.g., alkali metal carbonate salts added to commercial chlorite solutions to improve stability. Such lesser adjuvants must not alter, to any appreciable degree, rheology properties of the second part other than characteristic of the aqueous carrier itself. Once joined, the alkaline chlorine (III)/chlorite composition of the second part is blended into the acidic solution of the first part with resulting admixture having a buffered pH of approximately 3.0; whereupon, and by chemical reaction well known in the scientific art and literature, the disproportionation of chlorine (III)/chlorite occurs with a measured rate of formation of chlorine dioxide. Because this reaction begins immediately and because only very small quantities of chlorine dioxide are required for pronounced microbiocidal effect, the thus prepared mastitis control treatment is ready for application as soon as needed.
Commercial compositions of the invention are held within a user friendly dual or xe2x80x9cduetxe2x80x9d packaging combination designed to contain and transport parts A and B of these compositions together in predetermined and premeasured proportions and to be cooperative in the blending process wherein the user pours or otherwise causes the entire contents of package B, an equal or minor proportion, to be discharged into package A, an equal or major proportion, which then becomes the container and holding device for the admixture or final mastitis control treatment. The unique visual indicator or color stability maintains effective anti-mastitis protection by maintaining ClO2 activity while also maintaining a visual indicator or color.